There has conventionally been proposed an image forming system in which a plurality of PCs and an image forming apparatus such as an LBP (Laser Beam Printer) or multifunction apparatus are connected via a communication means such as a network. The image forming apparatus in the image forming system provides various functions, and these functions are generally graded in accordance with the cost or the like. For example, when a lineup of image forming apparatuses such as sister products is to be developed, only one basic program for controlling the operation of the apparatus is developed. A plurality of program modules which take on functions provided by the apparatus are installed in advance. Only program modules corresponding to the specifications of each apparatus are validated, providing functions corresponding to the product arrangement of the apparatus.
In some cases, a younger one of sister products is given options for achieving the same specifications as those of an elder sister product. The user who has purchased such product purchases an optional function and can use the new function. For a hardware optional function, when the hardware is mounted, the program module can be automatically validated by a mechanical or electrical identification means. For a purely software function or the like, the program module must be externally explicitly validated. As a validation means, a serviceman or the like conventionally connects an image forming apparatus to an apparatus dedicated to rewrite program identification information held by a launching program identification means, and rewrites the contents of the information. Alternatively, a program module is validated by inputting a password corresponding to the program module from the operation unit of the image forming apparatus, a PC connected to the image forming apparatus, or the like. In conventional program module validation, once a program module is validated, it permanently becomes valid.
This prior art poses the following problems.
More specifically, when a serviceman or the like uses a dedicated rewrite apparatus, as described above, the manufacture of the apparatus costs. The cost also rises because a serviceman or the like must go to a place where the apparatus is installed. The method of inputting a password suffers weak security because, if the password leaks, a user who cannot originally utilize the function can use the function. In the prior art, one rewrite apparatus or password is used for a given product, and rewrite cannot be done for each image forming apparatus, failing to take satisfactory measures against illegal use of the rewrite apparatus and leakage of a password. In the prior art, a program module which has been validated once can be permanently used, and may be illegally used for a long time.